A Field Book of the Stars Part 5

LIBRA (li-bra)--THE SCALES. (Face Southwest.)

LOCATION.--Libra is one of the signs of the zodiac, and lies between Virgo and Scorpius. Its two chief stars, a and , may be recognized west of and above the head of the Scorpion.

The star ? Libr is about 20 northwest of Antares in the Scorpion.

Spica in Virgo, a star of the first magnitude, is a little over 20 northwest of a Libr.

A quadrilateral is formed by the stars a, , ?, e, which characterizes the constellation.

The star a Libr looks elongated. An opera-gla.s.s shows that it has a fifth-magnitude companion.

is a pale green star. Its color is very unusual.

Lyra, Corona, and Hercules are almost directly overhead in the early evening, during July and August, and can best be observed in a reclining position. Thus placed, with an opera-gla.s.s to a.s.sist the vision, you may study to the best advantage the wonderful sight spread out before you, and search depths only measured by the power of your gla.s.s.

When the sun enters the sign Libra the days and nights are equal all over the world and seem to observe a certain equilibrium like a balance, hence the name of the constellation.

[Ill.u.s.tration: LIBRA]

CORONA BOREALIS (ko-ron bo-re-a-lis)--THE NORTHERN CROWN.

LOCATION.--A line drawn from a Cygni, to a Lyr, and projected a little over 40, terminates in the Crown, which lies between Hercules and Botes, and just above the diamond-shaped group of stars in the head of the Serpent.

The characteristic semicircle resembling a crown is easily traced out.

The princ.i.p.al stars are of the fourth magnitude excepting Gemma, which is a second-magnitude star and known as the "Pearl of the Crown."

Gemma, sometimes called Alphacca, forms with the stars Seginus and Arcturus, in Botes, an isosceles triangle, the vertex of which is at Arcturus.

Close to e a famous temporary appeared suddenly May 12, 1866, as a second-magnitude star. It was known as the "Blaze Star" and was visible to the naked eye only eight days, fading at that time to a tenth-magnitude star, and then rising to an eighth-magnitude, where it still remains.

The native Australians called this constellation "The Boomerang." To the Hebrews it was "Ataroth" and by this name it is known in the East to-day. No two of the seven stars composing the Crown are moving in the same direction or at the same rate.

a Coron is seventy-eight light years distant and sixty times brighter than the sun.

[Ill.u.s.tration: CORONA BOREALIS]

HERCULES (her-ku-lez)--THE KNEELER.

LOCATION.--A line drawn from either Vega, in Lyra, or Altair, in Aquila, to Gemma, in Corona Borealis, pa.s.ses through this constellation. The left foot of Hercules rests on the head of Draco, on the north, and his head nearly touches the head of Ophiuchus on the south.

The star in the head of Hercules, Ras Algethi, is about 25 southeast of Corona Borealis.

a Ophiuchi and a Herculis are only about 5 apart.

The cl.u.s.ter 13 M., the Halley Nebula, can be easily seen in an opera-gla.s.s. In a recent photograph of this cl.u.s.ter 50,000 stars are shown in an area of sky which would be entirely covered by the full moon.

Hercules occupies the part of the heavens toward which the sun is bearing the earth and planets at the rate of twelve miles a second or 373 million miles a year.

On a clear night the asterism Cerberus, the three-headed dog, which Hercules holds in his hand, can be seen.

This constellation is said to have been an object of worship in Phnicia. There is a good deal of mystery about its origin. The ancient Greeks called it "The Phantom" and "The Man upon his Knees."

The stars e, ?, ?, and p form a keystone shaped figure that serves to identify the constellation.

[Ill.u.s.tration: HERCULES]

BOTES (bo-otez)--THE HERDSMAN, OR BEAR DRIVER. (Face West.)

LOCATION.--Botes lies just west of the Crown, and east of Cor Caroli.

It may be easily distinguished by the position and splendor of its princ.i.p.al star, Arcturus, which shines with a golden yellow l.u.s.tre. It is about 35 east of Denebola, in Leo, and nearly as far north of Spica, in Virgo, and forms with these two a large equilateral triangle. A line drawn from ? to ? Urs Majoris and prolonged about 30 locates it, as does one from d Herculis to ? Coron prolonged its length.

The brightest stars in Botes outline a characteristic kite-shaped figure. Arcturus is mentioned in the Book of Job and is often referred to as "The Star of Job."

Three stars of the fourth magnitude are situated in the right hand.

They are about 5 north of ? Urs Majoris.

Contrast the color of Arcturus with Spica, Antares, and Vega.

The trapezium , ?, d, and , was called "The Female Wolves," by the Arabians; ?, ?, ? and ?, "The Whelps of the Hyenas." They knew the constellation as "The Vociferator."

Arcturus is the fourth brightest star in the northern hemisphere. It is 1000 times the size of our sun and rushes through s.p.a.ce toward Virgo at the astounding rate of ninety miles a second. It is forty light years distant.

The ancient Greeks called this constellation "Lycaon," a name which signifies a Wolf. The Hebrew name for it was "The Barking Dog."

[Ill.u.s.tration: BOTES]

VIRGO (ver-go)--THE VIRGIN. (Face West.)

LOCATION.--An imaginary line drawn from Antares in Scorpius through a Libr and prolonged a little over 20 strikes Spica, the brightest star in Virgo, which star is about 30 southwest of Arcturus.

Arcturus, Cor Caroli, Denebola, and Spica form a figure about 50 in length, called the Diamond of Virgo.